I am using a while loop to read a file and i have to delete a string from the last line. Here is the code so far:
I am able to replace that character from the last line of new.html, but still working on the variable data.
data=$(echo $data | sed s/||chr(/new thing/)
hi you must use sed fro this for simple way;)
sed -i '$s/chr/newchrr/' yourfile
read last line with
$s--> substitue "chr" to newchr in yourfile
-i --> edit(save) in place if you use gnu sed
or
sed '$s/chr/newchrr/' yourfile > tmpfile && mv tmpfile yourfile
regards
ygemici
@Skrynesaver:
I used
data=$(echo $data | sed s/||chr(//) -- to replace the string with empty space
and i got the following error (also tried a couple of different ways)
unexpected EOF while looking for matching `)'
I think my text was misleading - i have to replace the string '||chr( with an empty space and this has to be done only for the last line in the variable data got from the loop.
data=$(echo $data | sed 's/||chr(//')
thank you for your reply, as I have already mentioned I am able to do with the file say new.html (your file). But I am not yet able to achieve it for a variable got from the while loop.
If you have a similar solution for variable instead of filename, that will be really helpful.
I tried things like below to replace the string with empty which did not work. Basically i wanted to remove that string from the last line
sed '$s/'\''||chr(9)||/ /g' data > tmpfile.txt
sed '$s/'\''||chr(9)||/ /g' $data > tmpfile.txt
sed '$s/'\''||chr(9)||/ /g' ${data} > tmpfile.txt
If you want to use variables for file names:
mInp='MyInpFile'
mOut='MyOutFile'
sed '$s/.||chr(9)||//' ${mInp} > ${mOut}
# cat infile
first line
second line
third line '||chr( do not change this ok |(*0linuxisnotunix
last linee '||chr( change this ok |(*&^%
x=`wc -l <infile`;while read -r line; do [[ $x -eq 1 ]] && newlastline=$(echo $line|sed "s;'||chr(; ;");((x--));done<infile
echo "newlastline=$newlastline"
newlastline=last linee change this ok |(*&^%
if you update your file with new last line
# >newfile;x=`wc -l <infile`;while read -r line; do
[[ $x -eq 1 ]]&&newlastline=$(echo $line|sed "s;'||chr(; ;")&&echo "$newlastline">>newfile||echo "$line">>newfile
((x--));done<infile;more newfile
first line
second line
third line '||chr( do not change this ok |(*0linuxisnotunix
last linee change this ok |(*&^%
regards
ygemici
Thanks ygemici !
This works great, but I am not sure how to adapt this into my requirement as I had to manipulate it after the loop and not within. Can you also please explain the below part of the code :
sed "s;'||chr(; ;");
In my requirement I dont have a specific line number. So it will be easy if it can be manipulated after the loop is finished.
# cat infile
first line
second line
third line '||chr( do not change this ok |(*0linuxisnotunix
last linee '||chr( change this ok |(*&^%
actually , you can find with easily grep the your string which is the lines without any loop
# grep "'||chr(" infile -n|cut -d: -f1
3
4
then
you can change at 3.line your string with a space you can use this
# sed "3s;'||chr(; ;" infile
you can change at 4.line your string with a space you can use this
# sed "4s;'||chr(; ;" infile
"3s;'||chr(; ;"
//a little explanation//
" -> sed cmd begin
3s -> only edit 3 line
; -> sed exp separator
'||chr( -> your pattern
; ; --> this a space instead of your pattern (that changed with your pattern) [between semicolons]
; -> sed separator that is close sed cmd
" -> sed cmd finish (actually we tell our shell what is the sed parameters to called sed with these by shell)
Sorry for the late reply... i was trying a couple of other things too.. :wall:
When i tried to grep with a file name what u said below works... but it doesnt work with a variable name. Were u able to successfully execute this ? Is infile considered like a variable name ?
# grep "'||chr(" infile -n|cut -d: -f1
grep "'||chr(" new.html -n |cut -d: -f1 > new1.html works fine.
Also i did - man grep and the syntax seems to accept only file name.
With SED (accepts file and pipeline inputs), i was able to use a variable name but it wasnt able to replace the last line.. instead it replaced all lines...
This is what i used ( also tried simple examples)
name=`echo $data | sed '$s/'\''||chr(10)||/ /g'`
Expectation:
$s would replace in the last line
replace '||chr(10)|| with blank
Note: in my file there are more than one line that has that string similar to your example.
try this..
# data=`sed -n '$p' infile` ## take only last line
# name=`echo "$data" | sed '$s/'\''||chr(10)||/ /g'` ## change your pattern(s) with a space
# echo "$name" ## write your new value
regards
ygemici
Thanks for your effort and time.
I was working in the similar way, there were couple of glitches which i just fixed:
My code that worked:
#here it deletes the extra line added after the while loop
var1=`echo "$data" | sed '$d'`
#here it replaces as required
Replaced_Var=`echo "$var1" | sed '$s/'\''||chr(10)||//g'`
I have a few questions if anyone can answer or correct me: